Mazda's next-gen SkyActiv engines will drop spark plugs in favor of high compression

Mazda drops spark plugs.

That's pretty interesting. I mean the Skyactive 4s seem to push into the mid 40s on gas mileage, I wonder if this will get to 50s?

Keeping this emissions legal is going to be quite the feat. There's a lot of variables to carefully manage to make sure it burns how they want it...I am excited to see how it goes.

So... no ignition advance / retard?

So Mazda says it'll be out in 2018, then at the end of the article it says "... Mazda will begin mass production of EVs in 2019..."

So does that mean we finally get the gasoline technology we all wish we had for 50 years, only to have it replaced by EVs a year later? Hopefully they'll be produced in parallel for quite a while as it would make an attractive intermediate solution to going straight to an EV.

Are you telling me you made a time machine out of a........DeLorean?

In reply to kb58:

We wanted gas fueled diesel 50 years ago?

aircooled wrote: So... no ignition advance / retard?

Nope, just fuel advance / retard.

Yay!

My Ford ZX2 shot a spark plug out of the cylinder head and into the hood while driving one day, so I look at this as reduced parts count and failure modes.

Not really.

Still excited, though. This and camless valvetrains will bring ICE efficiencies into another world. That's cool.

alfadriver wrote: In reply to kb58: We wanted gas fueled diesel 50 years ago?

Drop it to 45 years ago, and yeah, that's about when Americans really started wishing there was a technology that could provide better performance, fuel economy, and emissions all at once.

I wonder how high it'll rev and how brappy a roughly 18:1 compression will sound.

All that being said, I foresee zero aftermarket modifications for them, though with the efficiency of extracting power, it likely won't need one.

I'm quite curious about throttle response withe 18:1 as well, that should be...eager. Could add even more fun the the mx-5.

aircooled wrote: So... no ignition advance / retard?

This was my thought as well.

Ignition timing via fuel injection timing, perhaps ??

I've said it before, and it bears repeating, the line between gas and diesel engines is becoming very blurry, thanks to GDI.

To be honest, I thought that camless valve trains would go mainstream before compression ignition gasoline power.

In reply to HappyAndy:

Other than HCCI, there's really little that blurs the line between Diesel and Otto.... And HCCI is technically Diesel.

Gas DI takes advantage of some evaporative physics at the expense of mechanical physics. But it's still VERY spark ignition and far closer to constant volume vs. constant pressure combustion.

So can you put a turbo on an HCCI engine?

In reply to alfadriver:

But wouldn't you say that HCCI is a further development of GDI, and doesn't GDI borrow heavily from diesel engeering? Precisely metered and timed fuel is being introduced at very high pressure directly into the combustion chamber, combustion pressures are steadily climbing due to both increases in static compression and forced induction, that sounds pretty diesely to a somewhat knowledgeable non-engineer. Now the static compression is solidly in diesel territory, and the spark plug is gone.

Will these engines have the same emissions issues (NOX) as true diesels, or does gasoline avoid that problem? Or is that not known yet?

SyntheticBlinkerFluid wrote: Are you telling me you made a time machine out of a........DeLorean?

This sucker's NUCLEAR?

This will be interesting. I was hoping to see another MS3 first but I doubt that'll ever happen again with this new Mazda boss.

alfadriver wrote: In reply to kb58: We wanted gas fueled diesel 50 years ago?

50 years ago, Mazda was selling gasoline engined cars that would run on Diesel, so... the circle is complete?

The more I think about this more fuel quality makes me wonder how this is going to to work. Not just grades, but the varying amounts of ethanol and summer/winter blends and high altitudes and..... I assume the engineers have this locked down, but I have so many questions.

The OEs are moving further and further ahead of the rest of us, and fast.

Keith Tanner wrote: The OEs are moving further and further ahead of the rest of us, and fast.

Heh, remember when a dozen guys in a garage could build a winning F1 car? It's almost like we're seeing that progress on the road.

In reply to Keith Tanner:

For the money and resources they've had all along, it's about damn time.

Driven5 wrote: In reply to Keith Tanner: For the money and resources they've had all along, it's about damn time.

Yeah, but let's don't forget that the auto companies have been stifling true innovation when it comes to efficiency for decades.

So a plugless engine followed by an electric, sounds like the components for a great hybrid.